Interspecific Eavesdropping
As part of my M.S. work at Texas Tech University, I studied the relationship between increasing predation risk and the foraging efficiency of cotton rats in west Texas. During a two-part experiment, I was able to find evidence that an indirect cue of predation risk, distance from burrow, decreased a cotton rats ability to discriminate between foraging trays that differed in resource (seed) abundance and to effectively find micropatches within trays. As the distance from burrows increased, cotton rats forging characteristics moved from that of a poor bayesian forager to that of a fixed-time forager. The second experiment was used to test predictions regarding the ability of cotton rats to eavesdrop on the vocalizations of heterospecifics that would provide information about the presence or absence of predators. Specifically, using a play-back experiment that utilized the alarm calls of Blue Jays , contact calls of the American Robin, and calls of Red-tailed Hawks, we were able to show that cotton rats foraging behaviors were altered. Their response indicated eavesdropping on Blue Jays, but not to any of the other species. Since the time of this and another similar study conducted using titmouse play backs and responses of chipmunks (Schmidt et al. 2008), more studies have shown the eavesdropping ability of multiple species. This work, along with many others have helped provide insight into the non-consumptive effects predators can have on prey, something that has since the time of my M.S. degree been referred to as the Ecology of Fear.
Bats Utilizing Bridges
-As an undergraduate at the University of North Carolina at Wilmington, I was given the opportunity as an Honor's project to study the roosting behavior of bats that utilized bridges as roosting sites in seven counties in southeastern North Carolina. From 2002-2003, I surveyed 423 bridges and culverts for the presence of bats. In the bridges where roost sites were located, I measure two environmental properties (light intensity and temperature), thought to influence roost site selection. Both properties were measure directly in the area where bats were discovered roosting and were compared to 6 points under bridges that had been chosen a priori. Results indicated bats preferred to roost in areas of bridges that were darker, and warmer than the 6 points chosen as controls. Three species of bats were observed during the study, Myotis austroriparius, Corynorhinus rafenisquii, Perimyotis subflavus.
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